Inner sole



July 23', 1935.

E. LATTEMANN INNER SOLE Filed Sept. 29, 1934 d v.2 nh I" A n .3:

Patented July 23, 1935 UNITED STATES PATENT orrlcr.

Application September 29, 1934, Serial No. 748,189 In Germany February 14, 1933 Claims. (Cl. 36-85) It is known to incise and perforate the inner sole in order to make it flexible. It has also been proposed to treat leather with oil or grease to make it flexible. A pad has already been fixed 5 on the inner sole by sewing.

This invention has for its object to produce a shoe, the sole of which is very flexible but remains durable notwithstanding the slits in the same. Another object of the invention is to keep the heel portion and the toe portion of the inner sole hard to ensure a good stiffening of the shoe notwithstanding the great flexibility of the treadsurface.

Novelty exists also in the employment of a support for weak insteps and of a heel wedge and the employment of a splay foot support. It is likewise new to provide a hole to more advantageously position the sustentaculum tali, hereinafter termed the heel bones.

The invention consists in that the inner sole, having incisions and holes under the ball of the foot, is rendered pliable by steeping with oil and the ball portion is covered with an insulating layer of soft material such as rubber, 'tarred felt or the like, which is covered with a thin 2 piece of upper leather separately secured, for

example stitched, at the edges, the holes in the inner sole registering with holes in the insulating layer and in the piece of upper leather and the stitching thread, also securing the insulating 3O layer, is pulled deeply into the leather and forms a padded edge, so that the flexible sole, which at the toe and heel is constructed as a hard inner sole, has at the ball portion a soft-tread surface increasing the flexibility of the sole and ensuring good ventilation of the foot. The foot may if desired rest directly on this tread portion.

By this construction a hard front and a hard heel portion of the inner sole and at'the same 40 time a good treading surface is obtained. Not only good flexibility of the treading surface is attained at the ball portion but a soft supporting surface is also formed. By steeping the perforated inner sole the strength of the incised portion of the inner sole leather is increased so that the inner sole will not tear. The flexibility of the sole is increased by the layer placed thereon. The foot has a soft bed at this point 50 and at the same time is insulated by the rubber layer in conjunction with the piece of upper leather. The perforations, however, ensure a good ventilation of the foot.

This construction, which meets a long felt 55 need of all orthopaedists, is attained by making this portion of the shoe as elastic as possible in such a manner that the toe portion absolutely controls theflexibility of the sole so that a swinging of the foot to the rear when rolling is rendered possible to a certain extent. The human foot can therefore swing to the rear like the foot of an animal so that the arch of the foot is strongly curved, which is not possible with a shoe with rigid sole. This new construction of the inner sole therefore effects a hygienically and anatomically great improvement especially important for the walking capacity of the foot.

By the combination of the features not an effect is attained which is obvious to anyone versed in the art, but an effect which results merely from the common eflfects of the features and which is the best obtainable. The invention consists in the combination of the different above mentioned features.

The invention can be carried out in various manners.

Two embodiments of the invention are illustrated by way of example in the accompanying drawing in which:

Fig. 1 shows a shoe in longitudinal section.

Fig. 2 is a top plan view with raised cover sole.

Fig. 3 is a section on line IIIIII of Fig. 1 on a larger scale.

Fig. 4 shows in top plan view a modified form of construction of the inner sole with cover sole.

The inner sole 1: has incisions b and holes 0 in the width of the ball portion. The ball portion has also been steeped in oil or the like so as to make it pliable and flexible.

In order to prevent the oil from oozing out upwards and greasing the foot and the sock, an insulating layer 11 oi. soft material such as rubber, tarred felt, cellulose, glass skin, or the like is arranged over the ball portion thus treated. If desired, thin pieces of rubber and leather may be employed for this purpose. This insulating layer d is covered by a piece of upper leather e, which is stitched for example at .f. The insulating layer d and also thepiece of upper leather e have holes a so that a .good ventilation is obtained in spite of the insulating layer covering the pliable greased inner sole at the ball. The piece of upper leather e forms a separate air chamber with the rubber layer.

The inner sole thus constructed is hard at the toe a and at the heel a so that a good stiffening of the shoe for working is ensured and also a good flexibility of the tread surface is obtained. The strength of the incised leather portion is 2 increased by saturating with oil and the flexibility of the sole is assisted bythe rubber layer d. The foot is insul-ated'by the applied rubber or tarred felt layer in combination with the piece of upper leather e. The whole is then covered by the cover sole h.

Figs. 2 and 3 show that, by arranging the stitching thread q at a certain distance from the edge of the sole, a soft pad edge r is formed above the ball part, which edge ensures a good support for the foot. Moreover this ensures that the cover sole cannot shift in any direction.

The inner sole is provided at about 1 /2 mm. from its edge with a channel 8 about 5 to 6 mm. in width and preferably of semicircular crosssection. This channel ensures that the seam q extending across the inner sole is deeply .embedded as illustrated on an enlarged scale in Fig. 3. Thus perspiration is prevented from reaching the thread. The sock cannot be destroyed by the thread q treated with pitch or wax.

The dot-dash circles show that the metatarsal bones I and 5 of the front portion of the foot have a soft bedding. The intermediate metatarsal bones 2, 3 and 4 are supported by the metatarsal support 1. Thus, a good splay foot support and a soft bedding for the metatarsal bones I and 5 is attained. A support for a weak instep is arranged at the rear on the sole on the inner side of the sole below the heel bone is called the sustentaculurn tali, which support consists of a supporting insert I slipped into a pocket or fixed. A heel wedge m is also provided which, in conjunction with the support for weak instep, forms a reinforcement for the heel.

The inner sole has a preferably lens-shaped or oval hole 11. about 2 cm. in diameter under the cover sole it below the os calcis. This hole registers with a hole in the outer sole. The edges n of the hole in the inner sole are bevelled as shown in Fig. 1, so as to produce a certain yieldability. The hole in the inner sole may be smaller because the os calcis tapers towards the bottom. The edge m may be skived in a circle of 4 cm. in diameter. Consequently the os calcis is resiliently bedded. The resilient effect may be increased by a rubber pad 17 which may be of ring shape.

By this new construction a bedding for the os calcis increasing in upward direction is formed, in that the os calcis can sink deeper relatively to the position of the joint.

In the form of construction illustrated in Fig. 4 the piece of upper leather e is extended towards the front so that a continuous cover sole is not required and only the rear portion is provided with a cover sole h. In this instance it is likewise advisable to embed the stitching thread in a similar manner to that shown in Fig. 3.

I claim:-

, 1. In a shoe the combination of a sole, an inner sole on said sole having incisions and perforations at the ball portion and rendered pliable by steeping in oil, a resilient insulating layer of soft material covering the ball portion of said inner sole, a separately fixed piece of thin upper leather covering said insulating layer, said insulating layer and said piece of upper leather having holes registering with the perforations in said inner sole, and seams connecting said insulating layer to each side of said inner sole pulled deeply into said insulating layer to form padded edges, whereby an inner sole hard at the toe and heel but soft at the ball portions is formed, the pliabiiity of the sole is increased and a treading surface is provided oifering good ventilation for the foot, and on which the foot rests directly.

2. In a shoe as specified in claim 1, a metatarsal support on the soft insulating layer adapted to support the second, third and fourth metatarsal bones, the first and fifth metatarsal bones resting softly on the padded layer.

3. In a shoe as specified in claim 1, an instep support arranged under the sustentaculum tali on the inner side of the insole, and a wedge provided on the heel portion of the inner sole, adapted in conjunction with said instep support to support the edge of the heel bone and form a recessed bedding therefore.

4. In a shoe as specified in claim 1, a cover sole over the inner sole having a hole at the os calcis portion, the inner sole having a hole registering with the hole in said cover sole, 8. bevelled portion surrounding the hole in said inner sole, and an elastic material in said bevelled portion adapted to form a recessed bedding for the os calcis and support the heel only around this bone.

5. In a shoe as specified in claim 1, the inner sole provided on its upper face with a channel of about to 6 mm. in width at a distance of about 1 mm. from the outer edges of the inner sole to facilitate the deep pulling and embedding of the seams.

EMIL LATTEMANN. 

